Java Data Type - 如何获得以天/小时/分钟/秒为单位的时间差

import java.util.Calendar;
import java.util.Date;

public class Main {
  private static final int SECOND = 1000;
  private static final int MINUTE = 60 * SECOND;
  private static final int HOUR = 60 * MINUTE;
  private static final int DAY = 24 * HOUR;

  public static void main(String[] args) {

    Calendar now = Calendar.getInstance();
    Date nowDate = now.getTime();

    long twoHoursByMillis = 2 * HOUR;
    long thirtyMinutesByMillis = 30 * MINUTE;

    Date twoHoursAndThirtyMinutesFromNow = new Date(twoHoursByMillis
        + thirtyMinutesByMillis);
    System.out.println(String.format("now %s and later %s", nowDate,
        twoHoursAndThirtyMinutesFromNow));

    long ms = 10304004543l;
    StringBuilder text = new StringBuilder("");
    if (ms > DAY) {
      text.append(ms / DAY).append(" days ");
      ms %= DAY;
    }
    if (ms > HOUR) {
      text.append(ms / HOUR).append(" hours ");
      ms %= HOUR;
    }
    if (ms > MINUTE) {
      text.append(ms / MINUTE).append(" minutes ");
      ms %= MINUTE;
    }
    if (ms > SECOND) {
      text.append(ms / SECOND).append(" seconds ");
      ms %= SECOND;
    }
    text.append(ms + " ms");
    System.out.println(text.toString());
  }
}